ree or four examples in illustration of what I mean.

First there is the ancient Riddle, that draws upon the imagination and
play of fancy. Readers will remember the riddle of the Sphinx, the
monster of Boeotia who propounded enigmas to the inhabitants and devoured
them if they failed to solve them. It was said that the Sphinx would
destroy herself if one of her riddles was ever correctly answered. It was
this: "What animal walks on four legs in the morning, two at noon, and
three in the evening?" It was explained by Oedipus, who pointed out that
man walked on his hands and feet in the morning of life, at the noon of
life he walked erect, and in the evening of his days he supported his
infirmities with a stick. When the Sphinx heard this explanation, she
dashed her head against a rock and immediately expired. This shows that
puzzle solvers may be really useful on occasion.

Then there is the riddle propounded by Samson. It is perhaps the first
prize competition in this line on record, the prize being thirty sheets
and thirty changes of garments for a correct solution. The riddle was
this: "Out of the eater came forth meat, and out of the strong came forth
sweetness." The answer was, "A honey-comb in the body of a dead lion."
To-day this sort of riddle survives in such a form as, "Why does a
chicken cross the road?" to which most people give the answer, "To get to
the other side;" though the correct reply is, "To worry the chauffeur."
It has degenerated into the conundrum, which is usually based on a mere
pun. For example, we have been asked from our infancy, "When is a door
not a door?" and here again the answer usually furnished ("When it is
a-jar") is not the correct one. It should be, "When it is a negress (an
egress)."

There is the large class of Letter Puzzles, which are based on the
little peculiarities of the language in which they are written--such as
anagrams, acrostics, word-squares, and charades. In this class we also
find palindromes, or words and sentences that read backwards and forwards
alike. These must be very ancient indeed, if it be true that Adam
introduced himself to Eve (in the English language, be it noted) with the
palindromic words, "Madam, I'm Adam," to which his consort replied with
the modest palindrome "Eve."

Then we have Arithmetical Puzzles, an immense class, full of diversity.
These range from the puzzle that the algebraist finds to be nothing but a
"simple equation," quite easy of d